Alternate Water Sources (Cloud Seeding)

The "warm rain" process, a type of cloud seeding usually involves clouds in tropical regions that never reach the freezing point. In these clouds, raindrops form around a "hygroscopic nuclei", a particle that attracts water such as salt or dust. Small droplets collide and coalesce until they form a drop large enough to fall. To encourage the "warm rain" process, calcium chloride is usually used to provide the nucleus for raindrop formation. The aircraft is flown above the clouds, then the aircraft drops the calcium chloride into the clouds.
The combination of cloud seeding, rooftop catchments and local water catchments can increase the overall amount of rainfall collected.